DSNT503I UNLOAD DATA SET `ddname` RECORD LENGTH SET TO `nnnnn`.

Explanation
 If the ddname is SYSRECnn, the record length specified
in the JCL for the data set is not large enough to contain an entire
row of unloaded data, or the record length was not specified in the
JCL.
 If the ddname is SYSPUNCH, the record length specified
in the JCL is not between 80 and 255, or the record length was not
specified in the JCL.

System action
 DB2® sets
the record length of the unload data set to the value specified in
the message text.

DSNT503I UNLOAD DATA SET ddname RECORD LENGTH SET TO nnnnn.

Explanation

System action

DSNT503I UNLOAD DATA SET `ddname` RECORD LENGTH SET TO `nnnnn`.